Current perpendicular to plane magnetoresistive sensor employing half metal alloys for improved sensor performance

Abstract

A magnetoresistive sensor having employing a Mn containing Huesler alloy for improved magnetoresistive performance in a structure that minimizes corrosion and Mn migration. The sensor can be constructed with a pinned layer structure that includes a lamination of layers of Co 2 MnX and CoFe, where X is Al, Ge or Si. The Co 2 MnX can be sandwiched between the layers of CoFe to prevent Mn migration into the spacer/barrier layer. The free layer can also be constructed as a lamination of Co 2 MnX and CoFe layers, and may also be constructed so that the Co 2 MnX layer is sandwiched between CoFe layers to prevent Mn migration.

What is claimed is: 
     
       1. A magnetoresistive sensor, comprising:
 a magnetic free layer structure; 
 a magnetic pinned layer structure comprising a lamination of layers including material selected from the group consisting of Co 2 [Mn 1-x Cr x ]Si, Co 2 [Mn 1-x Cr x ]Al or Co 2 [Mn 1-x Cr x ]Ge wherein the x is 0.05 to 0.1; and 
 a non-magnetic layer sandwiched between the free layer structure and the pinned layer structure. 
 
     
     
       2. A magnetoresistive sensor as in  claim 1  wherein the pinned layer structure further comprises first and second magnetic layer structures separated by an antiparallel coupling layer, the first magnetic layer structure being away from the non-magnetic layer and the second magnetic layer structure being adjacent to the non-magnetic layer, the first magnetic layer structure comprising CoFe and the second magnetic layer structure comprising the lamination of layers of CoFe and the material selected from the group consisting of Co 2 [Mn 1-x Cr x ]Si, Co 2 [Mn 1-x Cr x ]Al or Co 2 [Mn 1-x Cr x ]Ge. 
     
     
       3. A magnetoresistive sensor as in  claim 1  wherein the pinned layer structure further comprises first and second magnetic layer structures separated by an antiparallel coupling layer, the first magnetic layer structure being away from the non-magnetic layer and the second magnetic layer structure being adjacent to the non-magnetic layer, the first magnetic layer structure comprising CoFe and the second magnetic layer structure comprising a layer of material selected from the group consisting of Co 2 [Mn 1-x Cr x ]Si, Co 2 [Mn 1-x Cr x ]Al or Co 2 [Mn 1-x Cr x ]Ge sandwiched between layers of CoFe. 
     
     
       4. A magnetoresistive sensor as in  claim 1 , wherein the free layer structure comprises a lamination of layers of CoFe and a material selected from the group consisting of Co 2 [Mn 1-x Cr x ]Si, Co 2 [Mn 1-x Cr x ]Al or Co 2 [Mn 1-x Cr x ]Ge. 
     
     
       5. A magnetoresistive sensor as in  claim 1  wherein the free layer structure comprises first and second magnetic layer structures separated by an antiparallel coupling layer, the first magnetic layer structure being adjacent to the non-magnetic layer and comprising a layer of Co2MnX sandwiched between layers of CoFe, and the second magnetic layer structure comprising a layer of CoFe and a layer of NiFe. 
     
     
       6. A magnetoresistive sensor as in  claim 1  wherein the free layer structure comprises first and second magnetic layer structures separated by an antiparallel coupling layer, each of the first and second magnetic layer structures comprising a layer of Co2MnX sandwiched between layers of CoFe.